Information processing device

Abstract

The purpose of the present invention is to provide an information processing device capable of estimating communication quality in a mine with a small computational load and relatively high accuracy. An information processing device according to the present invention comprises: a storage unit that stores terrain information 300 indicating the terrain of a mine, position information indicating the position of a transmission station that transmits radio waves, and wireless communication parameters pertaining to wireless communication between the transmission station and a reception station; and a calculation unit that uses the terrain information 300, the position information, and the wireless communication parameters to generate a direct-wave power map 312 indicating the reception power, at each point in the mine, of direct waves of the radio waves transmitted from the transmission station. The calculation unit corrects (331) the reception power at each point in the direct-wave power map 312 on the basis of a distance difference between a point in the direct-wave power map 312 and one or more peripheral points around the point, and the reception power at the peripheral points in the direct-wave power map (see Fig. 3).

Description

Information processing device

[0001] The present invention relates to an information processing device.

[0002] There is a demand for connecting mining machines via wireless communication for the purpose of automating mines, etc. No matter where the mining machine moves within the mine, or even if the mine's topography changes due to mining, wireless communication between the mining machine and the base station must be maintained.

[0003] To this end, the system calculates the propagation conditions of radio waves and estimates the quality of wireless communication for each mining machine, thereby formulating and revising base station installation plans.

[0004] Patent Literature 1 discloses a technology for improving efficiency by mutually sharing information such that the output of a mining plan is used as the input of a network plan, and the output of the network plan is used as the input of a mining plan. Patent Literature 1 illustrates propagation calculation by ray tracing as an example for creating a network plan.

[0005] Special table 2019-509685 publication

[0006] In order to estimate the quality of wireless communication, it is necessary to calculate the degree to which the received power of radio waves transmitted from a transmitting station is attenuated before the radio waves reach a receiving station.

[0007] For example, ray tracing is one method for calculating the propagation attenuation of radio waves. Ray tracing requires taking into account many reflected waves in order to accurately calculate the received power, and when covering the entire vast area of ​​a mine, it requires an extremely large amount of calculation. For this reason, it is difficult to calculate the received power using ray tracing, which requires a large amount of calculation, every time the mine topography changes due to mining or the mining equipment moves. Therefore, it is difficult to calculate the received power while tracking the mine topography changes due to mining or the movement of mining equipment.

[0008] Therefore, the present invention has been made in consideration of the above problems, and aims to provide an information processing device that can estimate communication quality in a mine with a small amount of calculation and relatively high accuracy.

[0009] The information processing device of the present invention comprises a memory unit that stores topographical information indicating the topography of the mine, location information indicating the location of the transmitting station that transmits radio waves, and wireless communication parameters related to wireless communication between the transmitting station and the receiving station that receives the radio waves transmitted by the transmitting station, and a calculation unit that uses the topographical information, location information, and wireless communication parameters to generate a direct wave power map that indicates the received power of the direct waves of the radio waves transmitted from the transmitting station at each point in the mine, and the calculation unit corrects the received power at each point on the direct wave power map based on the distance difference between a point on the direct wave power map and one or more surrounding points around that point, and the received power at the surrounding points on the direct wave power map.

[0010] According to the information processing device of the present invention, it is possible to estimate the communication quality in a mine with a small amount of calculation and relatively high accuracy.

[0011] FIG. 1 is a schematic diagram showing a mine. FIG. 1 is a hardware block diagram of an information processing device. FIG. 2 is a diagram showing processing executed by an information processing device of Example 1. FIG. 3 is a diagram showing the contents of communication station parameters. FIG. 4 is a diagram showing the contents of a direct wave power map. FIG. 5 is a diagram showing the contents of a corrected power map. FIG. 6 is a conceptual diagram of direct wave derivation processing. FIG. 7 is a conceptual diagram showing the influence of terrain obstruction in direct wave derivation processing. FIG. 8 is a conceptual diagram of spatial correlation derivation processing. FIG. 9 is a conceptual diagram of deriving horizontal spatial correlation information and vertical spatial correlation information. FIG. 10 is a flowchart showing details of spatial correlation correction processing. FIG. 11 is a diagram showing processing executed by an information processing device of Example 2. FIG. 12 is a diagram showing processing executed by an information processing device of Example 3.

[0012] Hereinafter, the present embodiment will be described with reference to the accompanying drawings. In the accompanying drawings, functionally identical elements may be designated by the same numerals. Note that the accompanying drawings show embodiments and implementation examples according to the principles of the present disclosure, but these are for understanding the present disclosure and are not to be used to interpret the present disclosure in a limiting manner. The descriptions in this specification are merely typical examples and are not intended to limit the scope or application of the present disclosure in any way.

[0013] Although the present embodiment has been described in sufficient detail to enable those skilled in the art to practice the present disclosure, it should be understood that other implementations and forms are possible, and that changes in configuration and structure and substitutions of various elements are possible without departing from the scope and spirit of the technical ideas of the present disclosure. Therefore, the following description should not be interpreted as being limited thereto.

[0014] (Example 1) Fig. 1 is a plan view that schematically shows the entire mine 1. As shown in Fig. 1, various mining machines 4 are in operation in the mine 1, such as excavating machines such as shovels that excavate mineral resources, transport machines such as dump trucks that transport the mineral resources excavated by the excavating machines to smelting facilities and the like, and support vehicles for these machines. In this example, a case will be described in which the mining machine 4 is a transport machine such as a dump truck.

[0015] Also provided within the mine 1 is a control facility 5 that is capable of communicating with the mining machine 4. The control facility 5 receives various types of information from the mining machine 4, and transmits various commands such as operation commands and management information to the mining machine 4. Also provided within the control facility 5 is a remote control device (not shown) that operates the mining machine 4 from outside the mining machine 4. Note that the remote control device may be provided outside the mine 1.

[0016] The mine 1 is provided with a transmitting station 2 as a communication device between the mining machine 4 and the control equipment 5, which transmits radio waves from the control equipment 5 to the mining machine 4 and receives radio waves from the mining machine 4 to the control equipment 5, and a receiving station 3 which receives the radio waves transmitted from the transmitting station 2 and transmits the radio waves received by the transmitting station 2.

[0017] The transmitting station 2 is, for example, a fixed station, a base station, an access point, or an eNodeB (evolved NodeB). For example, the transmitting station 2 is communicably connected to a remote control device in the control facility 5 via a wired or wireless network. The transmitting station 2 transmits a remote operation instruction received from the remote control device to the mining machine 4. The receiving station 3 is, for example, mounted on the mining machine 4. The mining machine 4 (receiving station 3) receives the remote operation instruction transmitted from the transmitting station 2 and operates in accordance with the remote operation instruction. The receiving station 3 is, for example, a mobile station, a terminal, or a UE (User Equipment). Note that the mining machine 4 may be an unmanned dump truck or a manned dump truck. The receiving station 3 may also be provided outside the mining machine 4.

[0018] The information processing device 200 is a device that can communicate with the transmitting station 2 and the receiving station 3. The information processing device 200 may be installed inside the mine 1 or outside the mine 1. The configuration and operation of the information processing device 200 will be described later.

[0019] (Information Processing Device 200) The information processing device 200 of Example 1 creates a power map showing the received power at each point in the mine 1. The information processing device 200 is, for example, a personal computer, a smartphone, a tablet, a cloud server, or an on-premise server. As shown in FIG. 2 , the information processing device 200 has a calculation unit 201, a memory 202, a storage unit 203, a logic circuit 204, an interface 205, a bus 206, and a communication unit 207. Hereinafter, the interface will be abbreviated as I / F as appropriate. The calculation unit 201 is a CPU (Central Processing Unit), a GPU (Graphics Processing Unit), a DSP (Digital Signal Processor), or the like. The memory 202 is a dynamic random access memory (DRAM) or the like, and is used as a working area for the calculation unit 201. The storage unit 203 is a hard disk drive (HDD), a solid state drive (SSD), or a combination thereof, and stores various programs and various data. The logic circuit 204 is an application specific integrated circuit (ASIC) or a field programmable gate array (FPGA), or the like. The interface 205 is a device controller that controls the operation of peripheral devices (such as a keyboard, mouse, and display), a network controller that communicates information with external devices, or the like.

[0020] The calculation unit 201 or the logic circuit 204 is an example of a calculation unit of the present invention. The calculation unit 201, the logic circuit 204, or a combination thereof executes direct wave power derivation processing 311, spatial correlation derivation processing 321, and spatial correlation correction processing 331, which are described in FIG. 3 .

[0021] The storage unit 203 stores topographical information 300, communication station parameters 310, a direct wave power map 312, received power information 320, spatial correlation information 322, and a corrected power map 332, all of which are described in FIG.

[0022] The communication unit 207 transmits and receives data by communicating with devices outside the information processing device 200. For example, when data such as the topographical information 300, the communication station parameters 310, and the received power information 320 are not stored in the storage unit 203 in advance (or when the data is newly acquired), the communication unit 207 receives the data from a data source and stores it in the storage unit 203.

[0023] (Flow of wireless communication quality estimation method executed by information processing device 200) The flow of the wireless communication quality estimation method executed by the information processing device 200 of the first embodiment will be described with reference to Fig. 3. Rectangular blocks in Fig. 3 indicate processes executed by the information processing device 200, and parallelogram blocks indicate data stored in the information processing device 200. Note that in the following description of the wireless communication quality estimation method, calculations are described on the assumption that power, gain, and attenuation are each expressed as logarithmic values ​​in dB. Therefore, for example, addition of power or gain corresponds to multiplication in true values.

[0024] The information processing device 200 executes direct wave power derivation processing 311 using the topographical information 300 and communication station parameters 310 .

[0025] The topographical information 300 is information indicating the topography of the mine, and is, for example, DEM (Digital Elevation Model) data including altitude information for each coordinate. The topographical information 300 is created from the detection results obtained by, for example, a lidar, radar, or optical camera mounted on a drone, an aircraft, or a satellite. The communication unit 207 receives the created topographical information 300 and stores it in the memory unit 203. Alternatively, for example, known topographical information 300 may be stored in the memory unit 203 in advance.

[0026] As shown in FIG. 3A , the communication station parameters 310 include location information 350 of the transmitting station 2 and the receiving station 3 (the transmitting station 2 and the receiving station 3 are collectively referred to as communication stations), and wireless communication parameters 360 related to wireless communication of the communication stations. The location information 350 includes coordinates indicating the location of the transmitting station 2, the antenna height of the transmitting station 2, and the antenna height of the receiving station 3. In this embodiment, the antenna height of the receiving station 3 corresponds to the antenna height when an antenna is mounted on a mining machine 4 (a hydraulic excavator or a dump truck). The wireless communication parameters 360 include the transmission power of the wireless radio waves transmitted by the transmitting station 2, the transmitter gain (including the directivity and gain of the antenna of the transmitting station 2), the frequency band, the bandwidth, and the receiver gain (including the directivity and gain of the antenna of the receiving station 3). The communication unit 207 receives data describing this information as the communication station parameters 310 from an appropriate data source and stores the data in the storage unit 203. Alternatively, known information may be stored in advance in the storage unit 203 as the communication station parameters 310.

[0027] The direct wave power derivation process 311 generates a direct wave power map 312. The direct wave power map 312 shows the received power of the direct waves of the radio waves transmitted from the transmitting station 2 at each point in the mine 1. In other words, the direct wave power map 312 shows the power of the direct waves received when the receiving station 3 is located at that coordinate. As shown in FIG. 3B , the direct wave power map 312 is data in which the direct wave power (Pd(x, y)) is associated with the coordinates of each point in the mine 1.

[0028] Furthermore, the information processing device 200 executes a spatial correlation derivation process 321 using the received power information 320 .

[0029] The received power information 320 is, for example, a received power value for each coordinate actually measured by a mining machine 4 (dump truck) traveling within the mine 1 as the receiving station 3. The communication unit 207 receives the actual measured value from the mining machine 4, for example, by communicating with the mining machine 4, and stores the value in the storage unit 203 as the received power information 320.

[0030] The spatial correlation derivation process 321 generates spatial correlation information 322. The spatial correlation information 322 is information that corresponds the relative distance between two points within the mine 1 with the power difference caused by that relative distance. A larger value, i.e., a larger power difference, indicates a smaller correlation. The spatial correlation information 322 may have a single value for the entire mine 1, or different values ​​may be set for multiple areas within the mine 1. The multiple areas may be areas divided by a fixed distance range, such as 1 km x 1 km, or may be areas based on area attributes, such as a mining area or a transport route area.

[0031] Then, the information processing device 200 executes a spatial correlation correction process 331 using the topographical information 300 , the direct wave power map 312 , and the spatial correlation information 322 .

[0032] The spatial correlation correction process 331 creates a corrected power map 332. The corrected power map 332 shows the received power of radio waves transmitted from the transmitting station 2 at each point in the mine 1. In other words, the corrected power map 332 shows the power that would be received if the receiving station 3 were located at that coordinate. As shown in FIG. 3C , the corrected power map 332 is data in which the corrected received power (P(x, y)) is associated with the coordinates of each point in the mine 1.

[0033] (Direct wave power derivation process 311) In direct wave power derivation process 311, a direct wave power map 312 is created using topographical information 300 and communication station parameters 310, which shows the received power at each point in the mine of the direct waves of the radio waves transmitted from transmitting station 2. When power is expressed in logarithms below, the received power (direct wave power) at each point is calculated by the following formula: Direct wave power (Pd(x, y)) = transmitted power + transmitter gain + propagation gain + receiver gain

[0034] The transmitter gain and the receiver gain each include the gain of the antenna of the transmitting station 2 and the gain of the antenna of the receiving station 3. Furthermore, the propagation gain is a value obtained by adding a terrain shadowing gain to distance attenuation × (-1) calculated based on the distance between the transmitting station 2 and the receiving station 3. The distance attenuation is, for example, the squared attenuation of the distance according to the Friis formula. As shown in FIG. 4 , the terrain shadowing gain is a value determined by the shadowing caused by a shadowing object 400 between the transmitting station 2 and the receiving station 3. For example, the terrain shadowing gain is taken into consideration when the shadowing object 400 is present on a straight line 410 connecting the antenna of the transmitting station 2 and the antenna of the receiving station 3.

[0035] (Relationship Between Terrain Obstruction and Gain in Direct Wave Power Derivation Process) Fig. 5 is a diagram showing the relationship between terrain obstruction and gain in the direct wave power derivation process of Fig. 4. The horizontal axis of each graph in Fig. 5 is a parameter indicating the degree to which a obstruction 400 obstructs the line of sight between the transmitting station 2 and the receiving station 3, and the vertical axis is the gain when obstructed by the obstruction 400.

[0036] As shown in FIG. 5A, the radio wave may be regarded as a single ray, and the gain may be set to 0 if the obstruction by the obstruction 400 is below a certain level, and to −infinity if the obstruction is above a certain level.

[0037] 5B, the radio wave may be considered to have a certain degree of spread, and the gain may be reduced according to the degree of obstruction by the obstruction 400. As an example, knife edge diffraction or an approximation thereof may be used.

[0038] Regarding the obstruction 400, calculation may be performed only for the obstruction 400 that provides the greatest degree of obstruction between the transmitting station 2 and the receiving station 3, or an approximation such as the Bullington Method may be used in which multiple obstructions 400 are combined and treated as a single obstacle, or the gain may be calculated as a combination of diffractions caused by multiple obstructions 400.

[0039] Here, the obstruction 400 includes, for example, the terrain within the mine and the mining machine 4 itself. Therefore, the obstruction 400 that acts as a obstruction between the transmitting station 2 and the receiving station 3 may change over time.

[0040] (Spatial Correlation Derivation Process 321) In the spatial correlation derivation process 321, spatial correlation information 322 is derived, which corresponds the relative distance between two points in the mine 1 to the power difference caused by the relative distance.

[0041] In the first embodiment, when received power (received power information 320) and related information are acquired by the receiving station 3 mounted on the mining machine 4 traveling within the mine 1, the points where the received power was actually measured and the actual measured values ​​are used to derive spatial correlation information 322. Fig. 6(a) is a diagram showing the relationship between the difference in coordinate distance (horizontal axis) and the absolute value of the power difference (vertical axis) between the two points where the received power was acquired for multiple received powers acquired by the receiving station 3.

[0042] Based on the relationship in FIG. 6A, spatial correlation information 322 such as 601, 602, and 603 shown in FIG. 6B is created.

[0043] The spatial correlation information 322 may be, for example, spatial correlation information 601, which is a straight line with a slope that passes through power difference = 0 dB and distance difference = 0 m, or spatial correlation information 602, which is a straight line with a slope similar to spatial correlation information 601 when the distance difference is within a certain value but is terminated when the distance difference is equal to or greater than the certain value. Alternatively, it may be spatial correlation information 603, which is fixed at 0 dB when the distance difference is within a certain value and is terminated when the distance difference is equal to or greater than the certain value. The value of the spatial correlation information is a power value in dB.

[0044] The slope of the spatial correlation information 601 and 602 may be selected so that the least square error is smallest, or may be selected by multiplying the slope so that the least square error is smallest by a certain constant such as 0.5, or may be selected so that the number of data points below the line among all data points is a certain percentage or less (e.g., 80% or less).

[0045] The threshold for discontinuing the spatial correlation information 602 and 603 can be determined by, for example, determining the gradient using the same rules as those for deriving the gradient of the spatial correlation information 601 and 602 described above, and selecting a distance difference such that the product of the gradient and the distance difference is equal to or greater than a certain value such as 5 dB. The threshold for discontinuing the spatial correlation information 602 and 603 can be a fixed value (for example, 10 m), or the smaller of the fixed value and the product of the gradient and the distance difference can be selected.

[0046] (Horizontal Spatial Correlation Information, Vertical Spatial Correlation Information) The distance difference in Fig. 6 may be separated into a horizontal distance difference and a vertical (altitude) distance difference. Fig. 7 is a conceptual diagram of the spatial correlation derivation process 321 when the distance difference in Fig. 6 is separated into the horizontal and vertical directions.

[0047] As shown in Figure 7(a), for example, spatial correlation information 601 is derived in the same manner as the method for deriving spatial correlation information in Figure 6, with only the horizontal distance difference considered on the horizontal axis, and horizontal spatial correlation information (horizontal spatial correlation information) is derived. Next, for point 701, for example, at a horizontal distance of 20 m and a vertical distance of 10 m, a power difference 702 is obtained from the spatial correlation information 601 corresponding to a horizontal distance of 20 m. Then, a relationship (b) is obtained in which the power difference 702 corresponds to the vertical distance on the horizontal axis. For example, the horizontal axis corresponds to the vertical distance of 10 m, and the vertical axis corresponds to the value of the power difference 702. In this way, the relationship between the vertical distance and the power difference is derived for each point, and this relationship is used to create spatial correlation information corresponding to 601, 602, and 603 in Figure 6, thereby creating vertical spatial correlation information.

[0048] When creating the relationship between vertical distance and received power difference, if the power difference becomes negative during the above derivation process, or if the horizontal distance difference is greater than the truncation threshold for horizontal spatial correlation information, it is not included in the relationship between vertical distance and power difference.

[0049] (Spatial correlation correction process 331) In the spatial correlation correction process 331, the value (received power) at each point (each coordinate) on the direct wave power map 312 is smoothed using the values ​​(received power) at surrounding coordinates to create a corrected power map 332. At this time, the topographical information 300 is used to derive the distance difference between each point and the surrounding coordinates, and smoothing is performed based on the spatial correlation information 322 so as to be strongly influenced by the direct wave power at coordinates where the power difference corresponding to the derived distance difference is small.

[0050] (Details of Spatial Correlation Correction Processing) Fig. 8 is a flowchart showing details of the spatial correlation correction processing. Each step of the flowchart in Fig. 8 may be executed by the calculation unit 201 of the information processing device 200 executing a program, or may be executed by the logic circuit 204.

[0051] The information processing device 200 executes the following processes of S801 to S806 for all coordinates (x, y) within the mine 1 (S800).

[0052] The information processing device 200 acquires the direct wave power Pd(x, y) at the coordinates (x, y) from the direct wave power map 312 and substitutes it into the corrected received power P(x, y) (S801).

[0053] Next, the information processing device 200 performs loop processing for variables l and j from −N to N (S802). In this flowchart, loop processing is performed for variables l and j from −N to N, but it is also possible to perform loop processing for variable l from −N1 to N1 and loop processing for variable j from −N2 to N2.

[0054] The information processing device 200 determines whether the coordinates (x+l, y+j) of the surrounding point of the coordinates (x, y) are outside the range of the mine 1 (S803). If the information processing device 200 determines that the coordinates (x+l, y+j) of the surrounding point are outside the range of the mine 1 (S803: Yes), the information processing device 200 returns to S800. On the other hand, if the information processing device 200 determines that the coordinates (x+l, y+j) of the surrounding point are within the range of the mine 1 (S803: No), the information processing device 200 executes the processing of S804.

[0055] The information processing device 200 calculates the horizontal distance difference and the vertical distance difference between the coordinates (x, y) of the target point and the coordinates (x+l, y+j) of the surrounding points. Then, the information processing device 200 uses the horizontal spatial correlation information to obtain a horizontal spatial correlation Ch(l, j) (horizontal power difference) corresponding to the calculated horizontal distance difference, and uses the vertical spatial correlation information to obtain a vertical spatial correlation Cv(l, j) (vertical power difference) corresponding to the calculated vertical distance difference (S804).

[0056] Furthermore, the information processing device 200 acquires the direct wave power Pd(x+l, y+j) at the coordinates (x+l, y+j) from the direct wave power map 312 (S805).

[0057] The information processing device 200 calculates corrected received power (Pd(x+l,y+j)-Ch(l,j)-Cv(l,j)) using the horizontal spatial correlation Ch(l,j) and vertical spatial correlation Cv(l,j) acquired in S804, and the direct wave power Pd(x+l,y+j) acquired in S805. Then, the calculated corrected received power (Pd(x+l,y+j)-Ch(l,j)-Cv(l,j)) is compared with the corrected received power P(x,y) substituted in S801. If the comparison shows that the corrected received power (Pd(x+l,y+j)-Ch(l,j)-Cv(l,j)) is greater than P(x,y), the corrected received power P(x,y) is updated to Pd(x+l,y+j)-Ch(l,j)-Cv(l,j) (S806). Note that P, Pd, Ch, and Cv are values ​​in dB, and addition and subtraction are performed in dB.

[0058] The information processing device 200 determines whether the loop processing has ended (S807), and if it determines that the loop processing from -N to N for the above-mentioned variables l and j has not been completed, returns to S802 and executes the processing of S803 to S806 for the coordinates of the next surrounding point (x+l, y+j).

[0059] If the information processing device 200 determines that the loop processing from -N to N for the above-mentioned variables l and j has been completed, and determines that the spatial correlation correction processing has not been completed for all coordinates (x, y) within mine 1, it returns to S801 and executes the processing of S801 to S806 for the next coordinate (x, y).

[0060] If the information processing device 200 determines that the spatial correlation correction process has been completed for all coordinates (x, y) within the mine 1, it ends this flowchart (S808).

[0061] The order of the processes shown in the flowchart of FIG. 8 may be different from that of the flowchart of FIG. 8 as long as the final result is the same.

[0062] (Effects of Example 1) In Example 1, the corrected power map 332 can be obtained using the direct wave power map 312, which can be calculated with a smaller amount of calculation compared to ray tracing, which takes into account many reflected waves. Furthermore, in Example 1, by using spatial correlation information 322 instead of calculations regarding reflected waves, it is possible to obtain the corrected power map 332, which is not as accurate as when many reflected waves are taken into account, but has relatively high accuracy compared to the direct wave power map 312. Therefore, in Example 1, the communication quality in the mine 1 can be estimated with a small amount of calculation and relatively high accuracy.

[0063] Furthermore, in the first embodiment, when the condition of S806 is met, the direct wave power map 312 is corrected using the spatial correlation information 322, so that a point where radio waves are not reached or a point where the received power level is low on the direct wave power map 312 may become a point where radio waves are reached or a point where the received power level is high. By comparing the direct wave power map 312 before correction with the corrected power map 332 on a display or the like, it becomes possible to grasp the radio wave conditions in an area that cannot be grasped by the direct wave power map 312 alone.

[0064] The above-described estimation of communication quality makes it easier to plan and revise the network plan for mine 1, and allows the communication quality in mine 1 to be estimated in accordance with the ever-changing topography of mine 1 and the movement of mining machinery.

[0065] Furthermore, in a mine having a vast area such as an open-cut mine, a method for estimating communication quality in the mine 1 with a small amount of calculation and relatively high accuracy is effective.

[0066] (Example 2) In Example 1, a vehicle equipped with a receiving station was driven in the mine 1 to acquire the spatial correlation information 322, but the present invention is not limited to this. The spatial correlation information 322 in Example 2 may be a value that represents a fixed relationship that references values ​​used in other mines, for example.

[0067] Alternatively, the spatial correlation information 322 having a fixed relationship may be used as an initial value as in the second embodiment, and then the spatial correlation information 322 may be derived as in the spatial correlation derivation process 321 as in the first embodiment.

[0068] (Effects of Example 2) In Example 2, the spatial correlation information 322 used in other mines can be used, so there is no need to run a vehicle equipped with a receiving station through the mine 1 as in Example 1. For example, by using the spatial correlation information 322 of a mine with a similar shape, it is possible to accurately correct the direct wave power map 312. Other effects are the same as those of Example 1.

[0069] (Example 3) When a plurality of transmitting stations 2 exist in the mine 1, the processing equivalent to that of Example 1 and Example 2 is carried out for each transmitting station 2.

[0070] In the third embodiment, a corrected power map 332 is created for each of the plurality of transmitting stations 2. Then, an inter-station synthesis process 341 uses the plurality of corrected power maps 332 to create an inter-station synthesis power map 342 corresponding to the communication quality when the plurality of transmitting stations 2 are used.

[0071] In the inter-station synthesis process 341, for example, the fixed station with the greatest received power for each coordinate is selected as the connected fixed station, and the signal-to-interference power ratio is estimated assuming that transmission signals from fixed stations other than the connected fixed station interfere with the signal from the connected fixed station, and the signal-to-interference power ratio is used as the inter-station synthesis power map.

[0072] (Effects of the Third Embodiment) In the third embodiment, by creating the inter-station composite power map 342, it is possible to estimate the communication quality in the mine with relatively high accuracy even when there are multiple transmitting stations 2. Other effects are the same as those of the first embodiment.

[0073] The present invention is not limited to the above-described embodiments and includes various modifications. For example, the above-described embodiments have been described in detail to clearly explain the present invention, and are not necessarily limited to those including all of the described configurations. Furthermore, it is possible to replace part of the configuration of one embodiment with the configuration of another embodiment, or to add the configuration of another embodiment to the configuration of one embodiment. Furthermore, it is possible to add, delete, or replace part of the configuration of each embodiment with other configurations. Furthermore, the above-described configurations, functions, processing units, processing means, etc. may be implemented in hardware, in part or in whole, by designing them as integrated circuits, for example. Furthermore, the above-described configurations, functions, etc. may be implemented in software, in which a processor interprets and executes a program that implements each function.

[0074] For example, in the first embodiment, the horizontal spatial correlation Ch(l, j) and the vertical spatial correlation Cv(l, j) are acquired in S804 of Fig. 8, and the corrected received power P(x, y) is calculated using the horizontal spatial correlation Ch(l, j) and the vertical spatial correlation Cv(l, j) in S806. The present invention is not limited to this, and a spatial correlation may be acquired from a three-dimensional distance difference using any of 601 to 603 of Fig. 6, and the corrected received power P(x, y) may be calculated using the spatial correlation.

[0075] The transmitting station 2 and the receiving station 3 in the first to third embodiments may be transmitting and receiving stations that transmit and receive radio waves.

[0076] The information processing device of the present invention comprises: a memory unit that stores topographical information indicating the topography of the mine, location information indicating the location of a transmitting station that transmits radio waves, location information of a receiving station that is configured to be mounted on a mining machine operating within the mine and receives the radio waves transmitted from the transmitting station, and wireless communication parameters related to wireless communication between the transmitting station and the receiving station; and a calculation unit that uses the topographical information, the location information of the transmitting station, and the wireless communication parameters to calculate the received power of direct waves among the radio waves transmitted from the transmitting station at each point in the mine, and generates a direct wave power map that shows the distribution of the received power at each point based on the calculated value, when information regarding the actual measured value of the received power of the direct wave when the receiving station mounted on the mining machine receives the direct wave from the transmitting station is newly acquired, and corrects the received power at each point in the direct wave power map based on the first point at which the received power in the direct wave power map was calculated and the calculated value, the second point at which the received power was actually measured and the actual measured value, and the relative distance between the first point and the second point. According to the information processing device of the present invention, it is possible to estimate the communication quality in a mine with a small amount of calculation and relatively high accuracy. Specifically, it is possible to obtain the corrected power map 332 using the direct wave power map 312, which can be calculated with a small amount of calculation compared to ray tracing, which takes into account many reflected waves. Therefore, it is possible to estimate the communication quality in the mine 1 with a small amount of calculation and relatively high accuracy.

[0077] REFERENCE SIGNS LIST 1... mine, 2... transmitting station, 3... receiving station, 4... mining machine, 5... control facility, 200... information processing device, 201... calculation unit, 202... memory, 203... storage unit, 204... logic circuit, 205... interface, 206... bus, 300... terrain information, 310... communication station parameters, 311... direct wave power derivation processing, 312... direct wave power map, 320... received power information, 321... spatial correlation derivation processing, 322... spatial correlation information, 331... spatial correlation correction processing, 332... corrected power map, 341... inter-station synthesis processing, 342... inter-station synthesis power map, 350... position information of communication stations, 360... wireless communication parameters

Claims

1. A storage unit that stores terrain information indicating the terrain of a mine, position information indicating the position of a transmitter that transmits radio waves, position information of a receiver configured to be mounted on mining machinery operating in the mine and receive radio waves transmitted from the transmitter, and radio communication parameters related to the radio communication between the transmitter and the receiver; An arithmetic unit that calculates the received power of the direct wave among the radio waves transmitted from the transmitter at each point in the mine using the terrain information, the position information of the transmitter, and the radio communication parameters, and generates a direct wave power map showing the distribution of the received power at each point based on the calculated values; The arithmetic unit corrects the received power at each point in the direct wave power map based on information on the measured value of the received power of the direct wave when the receiver mounted on the mining machinery receives the direct wave from the transmitter, the first point at which the received power is calculated in the direct wave power map and its calculated value, the second point at which the received power is measured and its measured value, and the relative distance between the first point and the second point. An information processing apparatus characterized by the above.

2. The storage unit stores spatial correlation information in which the relative distance between two points in the mine and the power difference caused by the relative distance correspond; The arithmetic unit uses the spatial correlation information to obtain the power difference caused by the relative distance between the first point and the second point, and corrects the received power at each point in the direct wave power map based on the received power at the second point in the direct wave power map and the obtained power difference. The information processing apparatus according to claim 1, characterized by the above.

3. The spatial correlation information includes horizontal spatial correlation information in which a horizontal relative distance between two points in the mine and a power difference caused by the horizontal relative distance correspond, and vertical spatial correlation information in which a vertical relative distance between two points in the mine and a power difference caused by the vertical relative distance correspond. The calculation unit acquires a horizontal power difference corresponding to the horizontal relative distance between the first point and the second point in the direct wave power map using the horizontal spatial correlation information, and acquires a vertical power difference corresponding to the vertical relative distance between the first point and the second point in the direct wave power map using the vertical spatial correlation information. The information processing apparatus according to claim 2, characterized in that the received power at each point in the direct wave power map is corrected based on the received power, the horizontal power difference, and the vertical power difference at the second point in the direct wave power map.

4. The information processing apparatus according to claim 2, characterized in that the spatial correlation information is one piece of information set for the mine or information set for each of a plurality of areas in the mine.

5. The information processing apparatus according to claim 4, characterized in that the plurality of areas are a plurality of areas obtained by dividing the mine within a fixed distance range or areas for each attribute of the mine.

6. The information processing apparatus according to claim 2, characterized in that the spatial correlation information is generated based on the actually measured received power received by a mobile station moving in the mine from the transmitting station.

7. The information processing apparatus according to claim 2, characterized in that the spatial correlation information is spatial correlation information of another mine different from the mine.

8. When a plurality of transmitting stations are provided in the mine, the calculation unit generates a corrected power map in which the received power at each point in the direct wave power map is corrected for each of the plurality of transmitting stations, and generates a combined power map using the corrected power maps for each of the plurality of transmitting stations. The information processing apparatus according to claim 1, characterized in that.

9. The information processing apparatus according to claim 2, characterized in that when the corrected received power calculated using the received power at the second point in the direct wave power map and the acquired power difference is greater than the received power at the first point in the direct wave power map, the received power at the first point in the direct wave power map is corrected to the corrected received power.

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